RE: Difference between RPG III and RPG IV with CHAIN

[Kurt Anderson <kurt.anderson@xxxxxxxxxxxxxx>]

This should really be on the RPG list.

Both of those statements work in RPG IV.  It's hard to say what didn't work because I don't quite understand the problem you're explaining.  My guess is that the issue resulted from a confused use of BIFs.  CHAIN uses %found and can turn %eof off, but will not turn %eof on.  READ uses %eof and not %found.  (I apologize if you already know this.)

Style choice:  I would never use a Chain in a loop (unless the situation in particular called for it - I can't think of an example although I'm sure there is one, and it would be the exception to the rule).
 
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of jmmckee
Sent: Wednesday, November 04, 2009 4:00 PM
To: Midrange Systems Technical Discussion
Subject: Difference between RPG III and RPG IV with CHAIN

Where I work, training is something of a dirty word.

To read multiple records using a partial key in RPG III, I do this:

xxkey  chain   xxfmt                LR
*INLR  doweq  *OFF
  
  
xxkey  reade   xxfmt                         LR
           enddo


On a project a few years ago, written in RPG IV, that code did not work.

The only way we found to make it work was to do this:

xxkey    setll    xxfmt
xxkey     reade xxfmt                    
             dow    not %eof(xxfile)


xxkey    reade  xxfmt
             enddo


Doing a CHAIN to position and read the first record when multiple records were read just went to end of file, as I recall.  Been too long.

Were we doing someting wrong that caused the RPG IV code to fail?  This has really been bugging me for a long time.  I couldn't find a reason for the bizarre behavior in my searching.  It >may< have been an error when only one record with the matching subkey was found.  Again, I just don't remember.   

John McKee